There's never a simple answer because there's a lot more involved when it comes to legal agreements. And most people don't understand the intentional complications of legal language, which is why it's utilized. Agreeing to something doesn't always automatically include or bind all parties (developers, hosts, corporations...etc).
Quote: "As with any legal agreement both sides agree...". Nothing could be further from the truth. Legal language is used for one purpose, to deceive and confuse. Every word usually matters and if you read the majority of language used in online legal agreements you'll see plenty of "I agree" or "You agree". You almost never see "We agree". And that's a problem since one sided legal agreements aren't supposed to exist. But they do.
Sometimes the term "covenant" is used to get around the normal legal restrictions of a contract. Simply using the word "covenant" instead of "contract" allows one party to legally bind the other while allowing themselves to escape liability for any fraud, wrongdoing or other acts that would normally invalidate or nullify a legal contract.
But online agreements are usually just for show. Enforcing an online agreement that contains no signatures or proof of identity is next to impossible. An IP address is not enough to prove that a certain individual did in fact agree to online legal jargon.
Checking boxes is hardly a binding legal agreement. Especially since you can't show who actually checked the boxes. Friends use my computer all the time. Hackers can spoof IP addresses. The attempted enforcement of an online agreement would be interesting to watch play out in court.
You can post whatever legal mumbo jumbo you want online. Enforcing its validity is another matter.